JP2006147387A - Low-pressure discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a metal cap from getting loose from a tubular glass lamp container when a low-pressure discharge lamp is produced. <P>SOLUTION: Holes 5 made in bottom surfaces of metal caps 13 attached to both ends of the tubular glass lamp container 11 let off gas from an adhesive to prevent the metal caps 13 from getting loose from the tubular glass lamp container 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dielectric barrier discharge type low-pressure discharge lamp.

  A dielectric barrier discharge type low pressure discharge lamp having an electrode on the outer surface of a tubular glass lamp vessel is known from, for example, Japanese Patent Application Laid-Open No. 2002-8408 (Patent Document 1). FIG. 7 is a sectional view of such a conventional low-pressure discharge lamp 100 in the axial direction. In FIG. 7, reference numeral 11 denotes a tubular glass lamp container, and the inside of the tubular glass lamp container 11 is filled with a filler 4 made of a mixed gas of mercury and a rare gas. On the inner wall surface of the tubular glass lamp vessel 11, a phosphor layer 2 and a protective film layer 3 are formed. External electrodes 6 are formed on the outer surfaces of both ends of the tubular glass lamp vessel 11 by bonding and fixing a metal cap 12 with a conductive adhesive 9.

However, in such a conventional low-pressure discharge lamp, since the metal cap 12 has a bag shape, the gas generated during the heat treatment to cure the conductive adhesive 9 filled therein is the metal cap 5. Therefore, there is a problem that the metal cap 12 floats from the surface of the glass lamp vessel 11 due to the expansion of the gas generated at the bottom of the metal cap 12.
Japanese Patent Laid-Open No. 2002-8408

  The present invention has been made in view of the above-described conventional problems, and in the manufacturing process, the metal cap placed on both ends of the tubular glass lamp vessel is not floated by the gas generated from the conductive adhesive during the heat treatment, and it is ensured. Another object of the present invention is to provide a low-pressure discharge lamp that can be bonded to a glass lamp vessel.

  The low-pressure discharge lamp of the invention of claim 1 is characterized in that a metal cap is bonded to each outer surface of both ends of a tubular glass lamp vessel with a conductive adhesive, and a hole is provided in the bottom surface of the metal cap.

  According to a second aspect of the present invention, in the low-pressure discharge lamp according to the first aspect, a current conductor layer is provided between the inside of the conductive adhesive layer and the tubular glass lamp vessel.

  According to a third aspect of the present invention, in the low pressure discharge lamp according to the first or second aspect, the bottom surface of the metal cap has a flat shape.

  According to the present invention, the metal cap that covers both ends of the tubular glass lamp container during the manufacturing process does not float from the outer surface of the glass lamp container due to the expansion of the gas generated from the conductive adhesive during the heat treatment, and the metal cap is a glass lamp. It is possible to manufacture a low-pressure discharge lamp that is securely bonded to the outer surfaces of both ends of the container.

  Moreover, according to this invention, the edge part of a tubular glass lamp container can be inserted to the back of a metal cap, and the dispersion | variation in a lamp | ramp full length can be suppressed in a product.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  (First Embodiment) FIG. 1 is a sectional view in the axial direction of a low-pressure discharge lamp 1 according to a first embodiment of the present invention. In FIG. 1, 13 is a metal cap having a hole 5 at the bottom. An outer surface electrode 6 is formed by applying a conductive adhesive 9 to the inner wall of the metal cap 13 and covering and adhering to both outer surfaces of the tubular glass lamp vessel 11. The conductive adhesive 9 is made of a conductive filler (silver, nickel, carbon, etc.) and an adhesive (epoxy, silicone, polyimide, etc.).

  In the low-pressure discharge lamp 1 of the present embodiment, heat treatment is performed in order to cure the conductive adhesive 9 at the time of manufacture. The gas generated at that time can escape from the hole 5 at the bottom of the metal cap 13. The metal cap 13 does not float from the surface of the glass lamp container 11 and can be securely bonded and fixed. This makes it possible to manufacture a high-quality and stable low-pressure discharge lamp.

  (Second Embodiment) FIG. 2 shows a low-pressure discharge lamp 1 according to a second embodiment of the present invention. The present embodiment is characterized in that a current conductor layer 8 is provided between the conductive adhesive 9 and the tubular glass lamp vessel 11. A metal tape such as aluminum is used for the current conductor layer 8. The configuration of other parts is the same as that of the first embodiment shown in FIG.

  With such a configuration, in the second embodiment, a low-pressure discharge lamp with higher reliability can be obtained.

  (Third Embodiment) FIG. 3 is an axial sectional view of a low-pressure discharge lamp 1 according to a third embodiment of the present invention. In the shape of the metal cap 13 in the low-pressure discharge lamp of the above embodiment, since the bottom inner wall is a curved surface, the end portion of the tubular glass lamp container 11 cannot be inserted to the back of the metal cap 12, and therefore a large number of the caps. When the lamp is manufactured, the total length of the lamp may vary depending on the lamp. The present embodiment is characterized by improving this point.

  In FIG. 3, reference numeral 14 denotes a metal cap having a bottom surface processed into a flat shape and a hole 5 provided in the bottom surface. A conductive adhesive 9 is applied to the inner wall of the metal cap 14 and is covered and fixed to both ends of the tubular glass lamp vessel 11. Other configurations are the same as those of the first embodiment shown in FIG.

  According to the present embodiment, since the bottom surface of the metal cap 14 has a flat shape, it is possible to insert the end portion of the tubular glass lamp container 11 to the back of the metal cap 14. Therefore, it is possible to suppress variations in the total lamp length for each product during manufacture.

  (Fourth Embodiment) FIG. 4 shows a low-pressure discharge lamp 1 according to a fourth embodiment of the present invention. The present embodiment is characterized in that a current conductor layer 8 is provided between the conductive adhesive 9 and the tubular glass lamp vessel 11. According to the present embodiment, a metal tape such as aluminum is used for the current conductor layer 8 as in the second embodiment relative to the first embodiment.

  Thereby, also in this embodiment, high reliability can be obtained for the low-pressure discharge lamp.

  (Fifth Embodiment) FIG. 5 is a front view of a low-pressure discharge lamp 1 according to a fifth embodiment of the present invention, and FIG. 6 is an axial sectional view thereof. In the case of the low-pressure discharge lamp of each of the above embodiments, if the lamp is lit for a long time (3,000 to 5,000 hours), the adhesive is likely to be deteriorated by ultraviolet rays emitted from mercury and a rare gas while the lamp is lit. The embodiment is characterized by improving this point.

  In the low-pressure discharge lamp 1 according to the present embodiment, the phosphor layer 2 and the protective film layer 3 are formed on the inner surface of the tubular glass lamp container 11, and a mixed gas of mercury and a rare gas is formed inside the glass lamp container 11. Filler 4 is enclosed. A UV light shielding film 7 (metal thin film) is formed on the outer periphery of both ends of the glass lamp container 11, that is, on the formation part of the external electrode 6. A metal cap 14 is covered so as to cover the UV light shielding film 7. A conductive adhesive 9 is filled between the metal cap 14 and the UV light shielding film 7, and the metal cap 14 is bonded and fixed to the outer surface of the end portion of the glass lamp container 1 by the conductive adhesive 9. In this embodiment, the metal cap 14 having a flat bottom and the holes 5 formed therein is used. However, this may have the same shape as that of the first embodiment shown in FIG.

  The UV light shielding film 7 is a solder layer mainly composed of tin, for example. The conductive adhesive 9 is composed of a conductive filler (silver, nickel, carbon, etc.) and an adhesive (epoxy, silicone, polyimide, etc.).

  In the low-pressure discharge lamp 1 of the present embodiment, when a high frequency voltage is applied between the metal caps 14 at both ends of the lamp, the glass lamp container 1 passes through the conductive adhesive 9, the UV light shielding film 7 and the inner wall of the tubular glass lamp container 11. Electric power is injected into the lamp, and the lamp emits light, but ultraviolet rays emitted from mercury and rare gas during lamp operation are blocked by the UV light shielding film 7 and do not hit the conductive adhesive 9. For this reason, it can prevent that a conductive adhesive deteriorates by irradiation of an ultraviolet-ray during long-time lighting, and a metal cap comes off.

  Examples of the present invention will be described below in comparison with conventional comparative examples.

<Tubular glass lamp vessel>
Material: Borosilicate glass, Dimensions: Outer diameter 4.0mm, Inner diameter 3.0mm, Total length 750mm
<External electrode>
Conductive adhesive: Silicone adhesive + silver filler Metal cap: Copper + nickel plating (length 20 mm), with a hole in the bottom <phosphor layer>
Material: Three-wavelength phosphor, thickness: 20 μm
<Filler>
Filled gas: Neon and argon mixed gas (composition ratio: neon / argon = 90 mol% / 10 mol%)
Sealing pressure: 8kPa
Mercury: 3mg enclosed
The above is the first embodiment of the present invention. As Comparative Example 1, a low-pressure discharge lamp similar to that described above and having no hole in the metal cap was prepared.

  When 20 lamps were prototyped according to Example 1 and Comparative Example 1, 15 of 20 metal caps floated from the glass lamp container in Comparative Example 1, whereas in Example 1, the metal caps floated. There was nothing.

<Tubular glass lamp vessel>
Material: Borosilicate glass, Dimensions: Outer diameter 4.0 mm, Inner diameter 3.0 mm, Total length 750 mm
<External electrode>
Conductive adhesive: Silicone adhesive + silver filler Metal cap: Copper + nickel plating (length 20mm), flat bottom and perforated <phosphor layer>
Material: Three-wavelength phosphor, thickness: 20 μm
<Filler>
Filled gas: Neon and argon mixed gas (composition ratio: neon / argon = 90 mol% / 10 mol%)
Sealing pressure: 8kPa
Mercury: 3mg enclosed
The above is Example 2. Then, when 20 prototypes of Example 2 and Example 1 were produced, and when the lamp length tolerance was 750 ± 1 mm, in Example 1, 3 of the 20 lamps were out of tolerance. On the other hand, in Example 2, no lamp length was out of tolerance.

<Tubular glass lamp vessel>
Material: Borosilicate glass, Dimensions: Outer diameter 4 mm, Inner diameter 3 mm, Total length 700 mm
<Metal cap>
Material: Made of copper (nickel plating), Length: 19mm, Flat bottom and perforated <Conductive adhesive>
Silicone adhesive + silver filler <UV light shielding film>
Material: Lead-free solder, Length: 20mm
<Phosphor layer>
Material: Three-wavelength phosphor, thickness: 20 μm
<Filler> Filled gas: Neon + argon (10%) (total 60 torr) and mercury Then, as Comparative Example 2, a low-pressure discharge lamp similar to the above and having no UV light shielding film was prepared.

  When Example 3 and Comparative Example 2 were lit at a lamp current of 5 mA for 5000 hours, in Comparative Example 2, a metal cap was removed, but in Example 3, a metal cap was not removed.

1 is a sectional view in the axial direction of a low-pressure discharge lamp according to a first embodiment of the present invention. Sectional drawing of the axial direction of the low pressure discharge lamp of the 2nd Embodiment of this invention. Sectional drawing of the axial direction of the low pressure discharge lamp of the 3rd Embodiment of this invention. Sectional drawing of the axial direction of the low pressure discharge lamp of the 4th Embodiment of this invention. The front view of the low-pressure discharge lamp of the 3rd Embodiment of this invention. Sectional drawing of the axial direction of the low pressure discharge lamp of the 3rd Embodiment of this invention. Sectional drawing of the axial direction of the conventional low pressure discharge lamp.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Low pressure discharge lamp 2 Phosphor layer 3 Protective film layer 4 Filler 5 Hole 6 External electrode 7 UV light shielding film 8 Current conductor layer 9 Conductive adhesive 11 Tubular glass lamp vessel 13, 14 Metal cap

Claims (3)

  A low-pressure discharge lamp characterized in that a metal cap is bonded to each outer surface of both ends of a tubular glass lamp container with a conductive adhesive, and a hole is provided in the bottom surface of the metal cap.   2. The low-pressure discharge lamp according to claim 1, wherein a current conductor layer is provided between the inside of the conductive adhesive layer and the tubular glass lamp vessel. The low-pressure discharge lamp according to claim 1 or 2, wherein the bottom surface of the metal cap has a flat shape.

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